Mathematical models for the electrical activity in cardiac cells are normally formulated as systems of ordinary differential equations (ODEs). The equations are nonlinear and describe processes occurring on a wide range of time scales. Under normal accuracy requirements, this makes the systems stiff and therefore challenging to solve numerically. As standard implicit solvers are difficult to im...

Water quality management policies on a river basin scale are of special importance in order to prevent and/or reduce environmental pollution caused by human sources. Industrial effluents are a priority issue particularly in Urban Wastewater Systems (UWS) that receive mixed household and industrial wastewaters, apart from rainfall water. In this paper, we present an analysis and implementation o...

Shapiro et al. [2005; 2006], presented a framework for representing goal change in the situation calculus. In that framework, agents adopt a goal when requested to do so (by some agent reqr ), and they remain committed to the goal unless the request is cancelled by reqr . A common assumption in the agent theory literature, e.g., [Cohen and Levesque, 1990; Rao and Georgeff, 1991], is that achiev...

The situation calculus is one of the most established formalisms for reasoning about action and change. In this paper we will review the basics of Reiter’s version of the situation calculus, show how knowledge and time have been addressed in this framework, and point to some of the weaknesses of the situation calculus with respect to time. We then present a modal version of the situation calcul...

A fundamental aspect of general reasoning about physical systems is qualitative reasoning about continuous processes. The situation calculus is proposed as a framework for qualitative reasoning with some desirable properties that are less evident in the traditional framework, qualitative physics. However, in order to handle qualitative reasoning about continuous properties, we extend the concur...

A narrative is a course of real events about which we might have incomplete information. Formalisms for reasoning about action may be broadly divided into those which are narrative-based, such as the Event Calculus of Kowalski and Sergot, and those which reason on the level of hypothetical sequences of actions, in particular the Situation Calculus. This paper bridges the gap between these types...

Concurrent events are treated merely by not forbidding them. Narrative is treated as a collection of situations and events and relations among them. Narrative is easier than planning, because it does not require that the effects of events be guaranteed. Prediction is harder than planning, because it requires that the actions be inferred from the motives of the actors.